I hate to say it, but summer came to an end on Friday. That means it’s now time to cover up the swimming pool, switch off the air conditioner, and start preparing your home for the coming winter. When the temperatures begin to drop, you may start to notice that your windows are fogging up — or, in some cases, you’ve even got some water pooling in the sill area. Before you cry over your weeping windows, learn what they mean, what causes them, and how you can prevent windows from weeping altogether.

Why do windows weep?

If your windows are wet — or weeping, it indicates that you’ve got a moisture problem with your home. Even if you don’t notice the condensation on the windows, there are still some telltale signs that you’ve got some water problems. Look around your windows searching for signs of mildew, bubbling paint, or small amounts of water pooled in the window pan.

Left untreated, you could have major issues when it comes to mould and rot. With our Canadian climate, if water seeps past the exterior sheathing of the home, as it freezes and thaws, it can cause building materials, like masonry, to degrade much more quickly.

There are a few potential causes for that moisture buildup in your windows. Your home could be too airtight and doesn’t allow for a free exchange of moist air from your home with fresh air from the outside. A heat recovery ventilator can allow for that air exchange in your home.

Of course, the opposite problem can also cause moisture issues. If your home isn’t sealed properly, the warm air from your home and the cool air from the outside smash together causing condensation to build up around your windows. Check the insulation around your windows, as there may not be enough preventing that air flow.

In new homes, the building materials themselves could be full of moisture because they weren’t properly covered from the elements during the construction process. I’m talking homes that were built two years ago or less.

That said, the problem could be that your windows are no good and they need replacing. Before you make the purchase, make sure you’re checking for other issues, because new windows are an expensive fix — especially if they don’t end up solving your problem.

If you’ve searched high and low for the cause and have determined it’s time to replace your windows (if you’re still stumped, consider calling in a home inspector or window expert to help you source the root cause), here’s what to keep in mind when installing a new windows.

Installing new windows

I wouldn’t recommend taking on your new window installation as a DIY project. You can choose the best window on the market, but it won’t do you any good if it’s not installed properly. If installed incorrectly, your windows could leak air and water, and end up costing you a lot more money in the long run.

If you’re replacing your windows, make sure your contractor takes out the old window down to the rough stud and cleans it out completely. You want them to check for any evidence of damage or rot, and fix that before installing the new windows.

The window cavity should be properly insulated — I like using a low expansion spray foam to help keep the drafts out. To keep the water flowing away, I install a drainage system in the rough opening of the window pan that promotes the movement of water toward the exterior of your home. This prevents water from pooling up and causing that damage.

Basement windows and window wells

I once received a message from a homeowner who didn’t understand the purpose of the window wells along her basement windows, and wanted to fill hers in.

Believe me when I say that’s just asking for trouble. If you’re doing work in your basement and planning to install a larger egress window, you’ll likely have to install part of it below the grade. If you don’t plan for proper water drainage, you’ll see plenty of problems with wet windows.

Your window well is designed to collect water, drain it down to the weeping tile, and move it away from your home. Your window well should be filled with gravel, as well as include a vertical drainage pipe that leads water down through the soil towards your weeping tile — which keeps excess water moving away from your foundation. If possible, the lip of the window well should be a few inches (or several centimetres) above grade so water run-off and debris from the ground don’t flow back it.

A wet window can be a symptom of a few different root causes. Before you put in a new window, put on your detective hat and find the source of the problem. And when it is time to replace, call the right installer and make sure you’re keeping the water out.

Watch Mike Holmes in his new series, Holmes: Buy It Right on HGTV Canada. For more about Holmes, visit makeitright.ca.

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